Mkrepo

Changed

- Bump `boto3` version from 1.4.1 to 1.17.5.

Fixed

- RPM:
* Fix Python 3.6 compatibility by replacing the `removesuffix()` method, which
is available since Python 3.9.0, with another code.

Changed

- Use the `python3` shebang instead of `python` in the `mkrepo` executable path.
- Slightly update package description in `setup.py`.

Added

- Add auto-installation of required package dependencies.

Added

- RPM:
* Add support for deletion of stale repo metadata.

Changed

- RPM:
* Include 'primary' files into primary.xml.
* Add the `<rpm:conflicts>` section to primary.xml when it's needed.
* Not include 'primary' files and packages that are provided into the
`<rpm:requires>` section.
* Keep only the highest version of `libc.so.6` in the `<rpm:requires>`
section.

Fixed

- RPM:
* Process `I18NSTRING` header type entries.
* Handle `latin-1` chars in SUMMARY and DESCRIPTION headers.
* Fix wrong string representation of flags in the `<rpm:requires>`
tag entries.

Removed

- Completely drop support of Python 2.